Geenen Remy W F, Hussain Shahid M, Cademartiri Filippo, Poley Jan-Werner, Siersema Peter D, Krestin Gabriel P
Department of Radiology, Erasmus Medical Center, Dr Molenwaterplein 40, 3015 GD Rotterdam, The Netherlands.
Radiographics. 2004 Jan-Feb;24(1):e18. doi: 10.1148/rg.e18. Epub 2003 Oct 3.
In the last decade, computed tomographic (CT) and magnetic resonance (MR) colonography, two new cross-sectional techniques for imaging of the colon, emerged. Both techniques show promising initial results in the detection of polyps equal to or greater than 1 cm in diameter in symptomatic patients. Imaging protocols are still mostly under development and prone to change. Both CT and MR colonography generate a large number of source images, which have to be read carefully for filling defects and, if intravenous contrast material is used, enhancing lesions. An important postprocessing technique is multiplanar reformatting, which allows the viewer to see potential lesions in an orientation other than that of the source images. Virtual endoscopy, a volume rendering technique that generates images from within the colon lumen, is used for problem solving. CT and MR colonography have potential advantages over colonoscopy and double-contrast barium enema examination: multiplanar capabilities, detection of enhancing lesions that make the distinction between fecal residue and true lesion possible, and ante- and retrograde virtual colonoscopy. Currently, a number of studies suggest that patients have a preference for CT colonography over colonoscopy. Patients consider bowel cleansing the most uncomfortable part of any colon examination; hence, from the acceptance point of view, fecal tagging techniques are promising. Before CT and MR colonography can be implemented in daily practice, they must show approximately the same accuracy as colonoscopy for polyp detection in both symptomatic and screening patients.
在过去十年中，出现了两种用于结肠成像的新的横断面技术，即计算机断层扫描（CT）结肠成像和磁共振（MR）结肠成像。这两种技术在有症状患者中检测直径等于或大于1 cm的息肉方面均显示出有前景的初步结果。成像方案大多仍在开发中且易于更改。CT和MR结肠成像都会生成大量源图像，必须仔细读取这些图像以查找充盈缺损，并且如果使用静脉内对比剂，则要查找强化病变。一种重要的后处理技术是多平面重组，它使观察者能够从源图像以外的方向查看潜在病变。虚拟内镜检查是一种从结肠腔内生成图像的容积再现技术，用于解决问题。CT和MR结肠成像相对于结肠镜检查和双对比钡灌肠检查具有潜在优势：多平面功能、能够检测强化病变从而区分粪便残渣和真正病变，以及进行顺行和逆行虚拟结肠镜检查。目前，多项研究表明患者更喜欢CT结肠成像而非结肠镜检查。患者认为肠道清洁是任何结肠检查中最不舒服的部分；因此，从接受度角度来看，粪便标记技术很有前景。在CT和MR结肠成像能够在日常实践中应用之前，它们在有症状患者和筛查患者中检测息肉的准确性必须与结肠镜检查大致相同。
